As per the theory of evolution, man is the most highly evolved being.
In the human body the brain is of prime importance. The brain is a most
complex structure and has varied functions. Many mysteries of the brain
have been unravelled by neurophysiology, but there is one part of the
brain which has still remained an enigma. It is the prefrontal areas of
the frontal lobes of the cerebral cortex. This is the foremost part of
the brain situated just behind the forehead.

According to the process of evolution the brain is divided into an old
part, and a newly developed part. The prefrontal areas are the most recent
development of the new brain. These areas are not found in the lower animals.
They are present in a developed form only in the human brain. All these
years this part of the brain was called the 'silent area' because nothing
was known about its functions. No clinically discernible neurological
loss could be detected with a lesion in the prefrontal areas. An operative
procedure called lobotomy was tried in the earlier part of this century
for the cure of a mental disease known as schizophrenia. In this operation
the prefrontal areas were disconnected from the rest of the brain. The
person used to live without his mental illness but with hardly any human
qualities. He used to be a vegetative being.

Functions of the prefrontal areas

The prefrontal areas were supposed to be the seat of intelligence. Yet,
efforts to show that the prefrontal cortex is more important in higher
intellectual functions than other portions of the brain have not been
successful. In fact, destruction of the general interpretive area of Wernicke,
situated in the temporal lobe of the dominant (usually the left) hemisphere
of the brain causes infinitely more harm to the intellect than does the
destruction of both the prefrontal areas.

Research on the prefrontal areas is difficult, because:

They are not well-developed in the lower animals, on which experiments
are usually conducted.

They have abstract functions, which are subjective in nature, and
hence are difficult to evaluate objectively.

But by non-invasive techniques, like measuring the blood flow, it has
been shown that even the resting blood flow in the prefrontal cortex is
higher than that in other cerebral areas. The brain constitutes only 2%
of the body weight, yet it receives 20% of the entire circulating blood
volume. The cerebral cortex is the neuronal mass comprising 75% of the
brain of which the prefrontal areas constitute quite a major portion.,
Thus, even when the prefrontal areas are not obviously involved in any
activity, they are receiving a large amount of blood, which means they
have some higher, important function. It has also been shown that the
blood flow in the prefrontal areas increases with minor attempts at concentration
such as listening to digits and reciting them in a reverse order or sorting
out geometric figures according to shape, size and colour. If meditation
has been preceded by pranayama, the cerebral blood flow is still more
increased, as shown by the physiology of pranayama.

The functions of the prefrontal areas so far deduced are as follows:

To provide additional cortical area in which cerebration can take
place, so that the ability to learn complicated information is increased.

To control some types of behaviour, especially in regard to the choice
of behavioural options for each social or physical situation. For this
purpose the prefrontal areas transmit signals into the limbic area,
which controls the person's emotional behaviour and drive.

Prevention of distractability. A person without the prefrontal areas
is capable of performing intellectual tasks such as answering short
questions, or performing simple arithmetical computations. But he cannot
perform concerted, sequential thinking. He cannot carry out mental functions
directed to a specific goal.

Elaboration of thought, i.e. increase in the depth and abstraction
of thought.

Storage of many types of information simultaneously, and recall of
the same. If this faculty is lost, the person fails in many functions
of higher intelligence such as the abilities:

a) to prognosticate, i.e. to foresee future effects because he cannot
extrapolate past experience into the future, which is the basis of judgement,

b) to delay action in response to incoming sensory signals, so that
sensory information can be weighed until the best course of response
is decided.

c) ability to plan for the future

d) to consider the consequences of motor actions even before they are
performed.

e) to solve complicated mathematical, professional or philosophical
problems.

(iii) Has no embarrassment in relation to his excretory, sexual and
social activities.

(iv) Is highly distractable. He cannot concentrate on long complicated
thoughts.

Concentration and meditation

Meditation is the sheet-anchor of all the yogic practices. There may
be various ways but they all lead through meditation. There are many methods
of meditation, such as mantra japa, ajapa japa, siddha yoga, 'transcendental'
meditation, kundalini yoga, vipassana, etc. But the main principle in
all of them is 'concentration' in the early stages, followed by simple
'awareness' at the final level.

One may reach the levels of concentration and drawing in of senses, i.e.
pratyahara, through the physical processes of asana, pranayama, mudra
and bandha in hatha yoga and kriya yoga. One may concentrate on visual
symbols like a point, a flame, a lotus, a chakra, a yantra, an image of
ishta, or the visual image of Om. Another may use an auditory or verbal
japa of Om or any other mantra as used in mantra japa. A third may use
sound as in nada yoga, or the act of breathing as in ajapa japa, to gain
similar effects of concentration and pratyahara. One may concentrate on
an emotion like the love of a deity in bhakti yoga, or a thought or idea
in dhyana yoga. Even in the symbol-less meditation of vipassana of Buddha,
the idea of impermanence is used for concentration. Instead of a communicable
symbol like Om or an image, the sensations over the human body as a whole
are used for concentration in vipassana.

Meditation is developing the prefrontal areas

While learning the physiological functions of the prefrontal areas of
the frontal lobes of the: human cerebral cortex, we have noticed these
main functions:

Concentration.

Sequential abstract thinking.

Increasing the depth and abstraction of thought.

Control of reactions to external stimuli (thinking of the consequences,
and then choosing a particular response).

Ability to extrapolate past experience into the future, leading to:

a) judgement,

b) prognostication,

c) planning for the future.

Control of social and moral activities.

Control of quick emotional responses.

We have also seen that even simple acts needing some concentration increase
the blood flow of the prefrontal areas. Meditation which is concentration
in its purest form must be increasing the blood flow tremendously and
exercising the prefrontal areas, thus developing them to a still higher
level of performance and evolution.

At the beginning of the practice of meditation we associate some other
cerebral centre along with the prefrontal areas. If we use a visual symbol
we are employing the visual cortical centre along with the prefrontal
areas: Similarly with all other methods of meditation, we are employing
the corresponding cortical centres.

Blood flow measurement studies have shown that the blood flow in the
corresponding areas also increases along with that of the prefrontal areas.
These studies have not yet been done on the various meditative practices
but on simple mental exercises like counting and reciting or visual sorting
acts. They are worth a trial on the meditative practices.

In mantra japa the Brocka's area of speech is used. In laya yoga, the
auditory area is utilised. In bhakti yoga, the limbic area dealing with
emotions is involved. In dhyana yoga we bring into use the Wernicke's
general interpretive area concerned with verbal reasoning. In vipassana
we use the sensory cortex, while in ajapa japa we employ the motor cortex
while watching the act of breathing. Whatever other centre we may use,
we are employing the prefrontal areas to the maximum as concentration
is the main feature of elementary meditation, and concentration is the
function of the prefrontal areas.

As we progress further and further in meditation, we gradually do away
with these extra centres, until finally we remain only with prefrontal
areas in tune. This is the stage of savikalpa samadhi.

We do away with the visual symbols of point, flame, Om, swastika, ishta,
lotus, chakra and mantra. We dispense with the auditory symbols of laya
yoga and Om, and hear the anahata sound, which is nothing but the awareness
of the sensation of sound by the prefrontal areas. We do away with the
verbal symbols of various mantras. We do not remain concerned about the
body sensations of vipassana or the motor act of breathing. We go beyond
the emotions of bhakti yoga, and the processes of reasoning of gyana yoga.
We remain only with awareness, with the prefrontal areas.

Accept the experience

So many functions of the prefrontal areas are still remaining an enigma
and are likely to remain so for reasons given above. When subjective ideas
get involved in a scientific experiment, it no longer remains an experiment
but becomes a personal, subjective experience. This phenomenon has started
happening even in the natural sciences of subatomic physics. No wonder
that it should crop up when we are dealing with the human mind.

But, even from the list of functions of the prefrontal areas so far known,
one can deduce the achievements possible after the development of prefrontal
areas through meditation.

Control of reactions to external stimuli is obviously possible. The highest
levels of abstract thinking must have been achieved by the rishis through
meditation. No wonder they have reached Himalayan heights of imagination
and intuition to solve the mysteries of the universe, as expounded in
the Upanishads. Social behaviour is influenced. Tranquility of mind is
gained. The meaning of life is understood.

Through the practice of meditation we accelerate the process of evolution,
whose current phase appears to be the development of the prefrontal areas
of the human brain. This could be the arousal of super-consciousness.

The merging of the individual consciousness with the cosmic consciousness
as envisaged in nirvikalpa and other higher states of samadhi may be beyond
the domain of just human neuro-physiology.

This article is an attempt to correlate the contemporary knowledge of
the human neurophysiology to the practice of meditation. New scientific
knowledge may be added. At the same time, it is noted that meditation
is more of the nature of an experience than an experiment. This experience
is worth a trial even without knowing the 'How?' of it. Through meditation
we transcend the mind. Thus meditation has still some qualities not yet
understandable through our present knowledge of neuro-physiology. Hence,
the final advice would be to follow the various techniques of meditation,
and without expecting any result, practise with diligence and accept the
experience that one may attain.